//中文
var data_zh = ['你知道吗', '六月', '一日', '星期一', '是', '儿童节'];
//英语
var data_en = ['do you know', 'June', 'One day', 'Monday', 'Yes', 'Children\'s day'];

//左侧的语言显示
var btn_if = document.querySelectorAll("#btn_if button");

//右侧的语言显示
var btn_that = document.querySelectorAll("#btn_that button");

//点击切换语言
var btn_swap = document.querySelector("#btn_swap");

//左侧的输入内容
var text_if = document.querySelector("#text_if");

//右侧的翻译结果
var text_that = document.querySelector("#text_that");

//翻译按钮
var btn_res = document.querySelector("#btn_res");

//默认语言是中文
var lang = 'zh';

//切换语言
function lan() {
	if(lang == "zh") {
		lang = "en";
	} else {
		lang = "zh";
	}
	for(var i = 0; i < btn_if.length; i++) {
		btn_if[i].classList.remove("btn-primary");
		btn_if[i].classList.remove("btn-light");
		btn_that[i].classList.remove("btn-primary");
		btn_that[i].classList.remove("btn-light");
	}

	switch(lang) {
		case "zh":
			btn_if[0].classList.add("btn-primary");
			btn_if[1].classList.add("btn-light");
			btn_that[0].classList.add("btn-primary");
			btn_that[1].classList.add("btn-light");
			break;
		case "en":
			btn_if[0].classList.add("btn-light");
			btn_if[1].classList.add("btn-primary");
			btn_that[0].classList.add("btn-light");
			btn_that[1].classList.add("btn-primary");
			break;
	}
}

//点击翻译按钮的方法
function res() {
	//数据
	var data;
	//检测数据库里面有没有这个词汇
	var if_text = false;

	//看看中文词库里面有没有这个词语
	for(var i in data_zh) {
		if(text_if.value == data_zh[i]) {
			if_text = true;
			data = data_zh;
			text_that.value = data_en[i];

			if(lang == 'en') {
				lan();
			}
		}
	}

	//看看英语词库里面有没有这个词语
	for(var i in data_en) {
		if(text_if.value == data_en[i]) {
			if_text = true;
			data = data_en;
			text_that.value = data_zh[i];

			if(lang == "zh") {
				lan();
			}
		}
	}
	if(!if_text) {
		text_that.value = "";
		alert("无法翻译");
	}

}